Blackout screen on Xiaomi: causes and ways to eliminate

Your Xiaomi screen suddenly dims as if it were a gray veil? Or does brightness spontaneously decrease to a minimum despite the settings? Screen dimming is one of the most common problems with Redmi, POCO and Mi smartphones, but it can almost always be fixed without going to the service center. 80% of the time, it is not hardware malfunctions, but software failures or incorrect settings.

In this article, we’ll look at all the possible causes of screen darkening, from the banal power saving mode on to the rare firmware bugs, how to return brightness in 30 seconds (if the software is a problem), or what to do if the darkening is caused by physical damage to the matrix, and we’ve also compiled a table of methods that are compatible with popular Xiaomi models so that you don’t waste time on useless manipulations.

Before you start settings, check the obvious: whether you have manual brightness mode (a slider in the notification curtain) or adaptive backlight, which can fail in low light. If these parameters are fine, but the screen still looks like “under the veil” – read on.

1. Disconnect adaptive brightness and energy saving modes

The most common cause of screen dimming is automatic brightness control, which can malfunction. MIUI analyzes lighting through the sensor and adjusts the backlight, but sometimes the algorithm "gluts" by making the screen too dark even in bright light. Here's how to fix this:

Step 1. Open Settings → Display → Brightness and turn off the Adaptive Brightness slider. If it's already off, turn it back on, then deactivate it again, which will reset the sensor settings.

Step 2: Check the energy saving modes:

• 🔋 Settings → Battery. → Power Saving Mode – Select High Speed (if available).
• 🌙 Settings → Battery. → Super Power Saving – Turn off if the function is active.
• ⚡ If you POCO, Go to Settings. → Special facilities → Energy saving and deactivate all tumblers.

⚠️

Note: On some models (Redmi Note 8 Pro, Mi 9T) adaptive brightness can “hang” after the MIUI update. In this case, only resetting the display settings will help (more about this below).

2. Resetting the display settings to factory

If the dimming occurred after updating the firmware or installing a custom theme, most likely, the system settings of the screen were lost, resetting the display settings will return the brightness, contrast and color profile to factory values without affecting personal data.

Instructions:

1. Open the Settings. → The phone.
2. Tap 5 times on the MIUI version to activate the developer mode (if not already activated).
3. Return to the main settings menu and select Additional → Reset.
4. Click Reset Display settings and confirm the action.

After resetting, the screen can blink for 1-2 seconds, which is normal. If the dimming has disappeared, but after a while returned, the problem lies deeper (perhaps in the firmware or hardware).

Verification of the lighting sensor and calibration

If the adaptive brightness is on, but the screen remains dark even in a brightly lit room, the problem may be the light sensor, which is located next to the front camera and over time clogs or fails.

How to check the sensor:

• 🔦 Run Sensors (e.g. Sensor Test from Play Market).
• 📱 Cover the sensor with your finger – the illumination value should drop to 0-10 lux.
• ☀️ Point a flashlight at the sensor – the value should rise above 10,000 lux.

If the sensor doesn’t respond or shows inadequate values (e.g., 5,000 lux in the dark), try cleaning it with a soft brush (don’t use alcohol or sharp objects!).If that doesn’t help, the sensor is faulty – you will need a replacement at the service center.

⚠️

Attention: On models with OLED-screens (Mi 10, Mi 11, POCO F3) The light sensor may conflict with the function DC Dimming (reduce flickering). Try turning it off in Settings. → Display. → Reading mode.

4. Update firmware and reset to factory settings

Screen dimming often occurs after a failed MIUI update or firmware beta installation. If the problem occurs after the update, try the following steps:

Method 1: Reverse to a stable version:

Method 2: Complete reset (if the update didn't work):

⚠️

Note: On the POCO X3 and Redmi Note 9 Pro models, the bootloader may need to be re-activated after the reset (OEM Unlock in the developer settings).

💡

Before resetting, untie your Mi Account in Settings → Accounts, otherwise, after rebooting, the phone may require the username / password of the previous owner (Factory Reset Protection).

5. Hardware causes: matrix, plume, battery

If the software methods do not work, the screen dimming may be caused by physical malfunctions:

• 💡 Degradation OLED-Matrixes (typical for Mi 9, Mi 10 after 2-3 years of use).

How to diagnose:

• Light a flashlight at an angle on the screen – if you see a “shadow” or divorce, the problem is in the matrix.
• Shake the phone: if the image “floats” or vertical stripes appear, the plume is to blame.
• Check the back cover: if it is swollen, the battery needs an urgent replacement.

⚠️

Note: If the blackout is accompanied by purple or green stripes, in no case try to disassemble the phone yourself - this is a sign of detachment of the matrix.

💡

Hardware malfunctions cannot be fixed software. If the screen darkens after a fall or moisture, immediately bring the phone to the service - delay can lead to a complete failure of the display.

6. Hidden settings of the ADB developer and team

For power users: Some screen options are hidden in the developer menu or only available through ADB. These techniques can help if the standard settings don't work.

Method 1. High Brightness Mode (HBM) Disconnection

1. Activate the developer mode (5 taps according to the MIUI version).
2. Go to Settings. → Additionally. → For developers.
3. Find the option to turn off HBM and activate it.

Method 2: Reset screen calibration via ADB:

adb shell settings put system screen_brightness_mode 0


adb shell settings put system screen_brightness 204

(These commands will reset the brightness to factory values. Connect the phone to a PC with ADB installed.)

⚠️

Warning: Incorrect use of ADB can lead to a device blink. If you are not sure about your actions, skip this section.

7.Special cases: blackout in games, when charging, in the sun

Sometimes the screen only dims in specific situations. Here's what to do in each case:

FAQ: Frequent questions about Xiaomi screen dimming